Display device

ABSTRACT

According to one embodiment, a display device including a first substrate including a first insulating film and a second insulating film that includes a band-shaped first thick film portion, an island-shaped second thick film portion, a first contact hole penetrating the first thick film portion, and a second contact hole penetrating the second thick film portion, a first thickness of the first thick film portion and a second thickness of the second thick film portion are larger than a film thickness of the second insulating film between the first and second thick film portions, and a second substrate comprises a spacer overlapping the first thick film portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2021-047325, filed Mar. 22, 2021, theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a display device.

BACKGROUND

In recent years, various display devices with built-in touch sensorshave been proposed. In one example, a display device is disclosed inwhich a plurality of electrodes formed on a display panel play the roleof sensor electrodes when in a touch sensing mode and play the role ofcommon electrodes when in a display mode. As a touch sensing method,either a mutual-capacitive method or a self-capacitive method isapplied. In the touch sensing mode, sensing is performed by applying atouch drive voltage to the sensor electrode through a signal line.

In a display device equipped with a touch sensor in which island-shapedsensor electrodes are lined up in a matrix, a structure is known inwhich the pixel electrode is connected to a semiconductor layer viathree layers of electrodes, which are a drain electrode on the samelayer as a signal line, a metal electrode on the same layer as a metalline, and a transparent electrode on the same layer as the sensorelectrode.

The display device is also equipped with a spacer to maintain a cell gapbetween first and second substrates. For example, a configuration inwhich the spacer disposed on the first substrate and the spacer disposedon the second substrate intersect and face each other is known. Thisconfiguration can suppress the occurrence of scraping, etc., of analignment film by the spacer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view showing the appearance of a display device of thepresent embodiment.

FIG. 2 is a plan view showing a configuration example of a touch sensor.

FIG. 3 is a plan view showing the relationship between a pixel and asensor electrode shown in FIG. 2.

FIG. 4 shows a basic configuration and an equivalent circuit of a pixel.

FIG. 5 is a plan view showing an example of a pixel layout.

FIG. 6 is a plan view showing the periphery of a subspacer.

FIG. 7 is a cross-sectional view of a display panel taken along line A-Bshown in FIG. 6.

FIG. 8 is a cross-sectional view showing a state in which an externalforce is applied to the display panel shown in FIG. 7.

FIG. 9 is a cross-sectional view of the display panel taken along lineC-D shown in FIG. 6.

FIG. 10 is a plan view showing the periphery of a main spacer.

FIG. 11 is a cross-sectional view of the display panel taken along lineE-F shown in FIG. 10.

FIG. 12 is a plan view showing the periphery of a subspacer.

FIG. 13 is a plan view showing the periphery of a main spacer.

FIG. 14 shows a dummy line.

FIG. 15 shows a metal line.

DETAILED DESCRIPTION

In general, according to one embodiment, a display device comprising afirst substrate, a second substrate facing the first substrate, and aliquid crystal layer located between the first substrate and the secondsubstrate, wherein the first substrate comprises a scanning lineextending in a first direction, a first signal line extending in asecond direction intersecting the first direction, a first insulatingfilm covering the first signal line, a first metal line disposed on thefirst insulating film and extending in a manner overlapping the firstsignal line, an island-shaped metal electrode disposed on the firstinsulating film and formed by the same material as the first metal line,a second insulating film covering the first metal line and the metalelectrode, and a common electrode disposed on the second insulatingfilm, the second insulating film comprises, a band-shaped first thickfilm portion extending in the first direction and overlapping thescanning line and the metal electrode, an island-shaped second thickfilm portion overlapping the first metal line and the common electrode,a first contact hole penetrating the first thick film portion to themetal electrode, and a second contact hole penetrating the second thickfilm portion to the first metal line, a first thickness of the firstthick film portion and a second thickness of the second thick filmportion are larger than a film thickness of the second insulating filmbetween the first thick film portion and the second thick film portion,and the second substrate comprises a spacer that protrudes toward thefirst substrate and overlaps the first thick film portion.

Embodiments will be described hereinafter with reference to theaccompanying drawings. The disclosure is merely an example, and properchanges within the spirit of the invention, which are easily conceivableby a skilled person, are included in the scope of the invention as amatter of course. In addition, in some cases, in order to make thedescription clearer, the widths, thicknesses, shapes, etc., of therespective parts are schematically illustrated in the drawings, comparedto the actual modes. However, the schematic illustration is merely anexample, and adds no restrictions to the interpretation of theinvention. Besides, in the specification and drawings, the same orsimilar elements as or to those described in connection with precedingdrawings or those exhibiting similar functions are denoted by likereference numerals, and a detailed description thereof is omitted unlessotherwise necessary.

First Embodiment

First, a display device DSP according to the present embodiment will bedescribed in detail. In the present embodiment, a case in which thedisplay device DSP is a liquid crystal display is described.

FIG. 1 is a plan view showing the appearance of a display device of thepresent embodiment. In the following descriptions, for example, a firstdirection X, a second direction Y and a third direction Z are orthogonalto each other, but they may intersect at an angle other than 90 degrees.The first direction X and the second direction Y correspond to thedirections parallel to a main surface of a substrate that constitutesthe display device DSP. The third direction Z is equivalent to athickness direction of the display device DSP. In the followingdescriptions, a direction forwarding a tip of an arrow indicating thethird direction Z is referred to as “upward” and a direction forwardingoppositely from the tip of the arrow is referred to as “downward”.Further, when it is assumed that there is an observation position toobserve the display device DSP on a tip side of an arrow in a thirddirection Z, viewing from this observation position toward the X-Y planedefined by the first direction X and the second direction Y is referredto as a planar view.

Here, a plan view of the display device DSP in the X-Y plane is shown.The display device DSP comprises a display panel PNL, a flexible printedcircuit board 1, an IC chip 2, and a circuit board 3.

The display panel PNL is a liquid crystal display panel and comprises afirst substrate SUB1, a second substrate SUB2, a seal SE, alight-shielding layer BM, spacers SP1 to SP4, and a liquid crystal layerLC to be described later. The display panel PNL also comprises a displaysection DA that displays images and a frame-shaped non-display sectionNDA that surrounds the display section DA. The second substrate SUB2faces the first substrate SUB1. The first substrate SUB1 includes amounting section MA that is extended in the second direction Y more thanthe second substrate SUB2. The first substrate SUB 1 is a semiconductorsubstrate including a plurality of thin-film transistors and may bereferred to as an array substrate. The second substrate SUB2 includes acolor filter layer CF as described below, and may be referred to as acolor filter substrate.

The seal SE is located in the non-display section NDA and adheres thefirst substrate SUB1 and the second substrate SUB2. The light-shieldinglayer BM is located in the non-display section NDA. The seal SE islocated at a position superposing the light-shielding layer BM in planarview. In FIG. 1, an area in which the seal SE is disposed and an area inwhich the light-shielding layer BM is disposed are shown by differentdiagonal lines, and an area in which the seal SE and the light-shieldinglayer BM superpose is shown by cross-hatching. The light-shielding layerBM is provided on the second substrate SUB2.

The spacers SP1 to SP4 are all located in the non-display section NDA.The spacer SP1 is located at the outermost periphery of the displaypanel PNL. The spacer SP2 is located more on the display section DA sidethan the spacer SP1. The spacers SP1 and SP2 are superposed on the sealSE. The spacers SP3 and SP4 are located more on the display section DAside than the seal SE.

The display section DA is located inside an area surrounded by thelight-shielding layer BM. The display panel PNL comprises a plurality ofpixels PX arranged in a matrix in a first direction X and the seconddirection Y in the display section DA.

The flexible printed circuit board 1 is mounted on the mounting sectionMA and connected to the circuit board 3. The IC chip 2 is mounted on theflexible printed circuit board 1. Note that the IC chip 2 may be mountedon the mounting section MA. The IC chip 2 has a built-in display driverDD that outputs signals necessary for displaying images in a displaymode that displays images. In the example shown in the drawing, the ICchip 2 has a built-in touch controller TC that controls a touch sensingmode to detect the approach or contact of an object to the displaydevice DSP. In the drawing, the IC chip 2 is shown with a dashed line,and the display driver DD and the touch controller TC are shown withdotted lines.

The display panel PNL of the present embodiment may be one of atransmissive type provided with a transmissive display function thatdisplays images by selectively transmitting light from the rear side ofthe first substrate SUB1, a reflective type provided with a reflectivedisplay function that displays images by selectively reflecting lightfrom the front side of the second substrate SUB2, and asemi-transmissive type provided with the transmissive display functionand the reflective display function.

The detailed configuration of the display panel PNL is omitted here.However, the display panel PNL may be provided with any of the followingconfigurations corresponding to a display mode that uses a horizontalelectric field along the substrate main surface, a display mode thatuses a vertical electric field along the normal line of the substratemain surface, a display mode that uses a tilted electric field inclinedin an oblique direction to the substrate main surface, and, further, adisplay mode that uses a combination of the above horizontal electricfield, vertical electric field, and tilted electric field asappropriate. The substrate main surface here is a surface parallel tothe X-Y plane defined by the first direction X and the second directionY.

FIG. 2 shows a plan view of a configuration example of a touch sensorTS. Here, a self-capacitive type touch sensor TS is described; however,the touch sensor TS may also be a mutual-capacitive type.

The touch sensor TS comprises a plurality of sensor electrodes Rx (Rx1,Rx2 . . . ) arranged in a matrix and a plurality of sensor lines L (L1,L2 . . . ). The plurality of sensor electrodes Rx are located in thedisplay section DA and are arranged in a matrix in the first direction Xand the second direction Y. One sensor electrode Rx configures onesensor block B. A sensor block B is the smallest unit capable of touchsensing. The plurality of sensor lines L extend along the seconddirection Y and are lined up in the first direction X, respectively, inthe display section DA. Each of the sensor lines L is provided, forexample, at a position superposed on the signal line S which will bedescribed later. Each of the sensor lines L is pulled out to thenon-display section NDA and electrically connected to the IC chip 2 viathe flexible printed circuit board 1.

Here, the relationship between the sensor lines L1 to L3 lined up in thefirst direction X and the sensor electrodes Rx1 to Rx3 lined up in thesecond direction Y will be focused. The sensor line L1 is superposed onthe sensor electrodes Rx1 to Rx3, and is electrically connected to thesensor electrode Rx1.

The sensor line L2 is superposed on the sensor electrodes Rx2 and Rx3,and is electrically connected to the sensor electrode Rx2. A dummy lineD20 is separated from the sensor line L2. The dummy line D20 issuperposed on the sensor electrode Rx1 and is electrically connected tothe sensor electrode Rx1. The sensor line L2 and the dummy line D20 arelocated on the same signal line.

The sensor line L3 is superposed on the sensor electrode Rx3 and iselectrically connected to the sensor electrode Rx3. A dummy line D31 issuperposed on the sensor electrode Rx1 and is electrically connected tothe sensor electrode Rx1. A dummy line D32 is separated from dummy lineD31 and the sensor line L3. The dummy line D32 is superposed on thesensor electrode Rx2 and is electrically connected to the sensorelectrode Rx2. The sensor line L3 and the dummy lines D31 and D32 arelocated on the same signal line.

In the touch sensing mode, the touch controller TC applies a touch drivevoltage to the sensor line L. As a result, the touch drive voltage isapplied to the sensor electrode Rx, and sensing is performed at thesensor electrode Rx. A sensor signal corresponding to the sensing resultat the sensor electrode Rx is output to the touch controller TC via thesensor line L. The touch controller TC or an external host detects thepresence or absence of the approach or contact of an object to thedisplay device DSP and the position coordinates of the object based onthe sensor signal.

Note that, in the display mode, the sensor electrode Rx functions as acommon electrode to which a common voltage (Vcom) is applied. The commonvoltage is applied via the sensor line L from the voltage supply unitincluded in, for example, the display driver DD.

FIG. 3 is a plan view showing the relationship between the pixel PX andthe sensor electrode Rx shown in FIG. 2. In FIG. 3, a direction thatintersects the second direction Y counterclockwise at an acute angle isdefined as a direction D1, and a direction that intersects the seconddirection Y clockwise at an acute angle is defined as a direction D2.Note that an angle θ1 between the second direction Y and the directionD1 is almost the same as an angle θ2 between the second direction Y andthe direction D2.

One sensor electrode Rx is disposed over a plurality of pixels PX. Eachpixel PX includes a portion extending along the direction D1 and aportion extending along the direction D2. Note that the pixel PX hereindicates the smallest unit that can be individually controlledaccording to a pixel signal, and may sometimes be referred to as asub-pixel. The smallest unit to realize color display may sometimes bereferred to as a main pixel MP. The main pixel MP is configured bycomprising a plurality of sub-pixels PX that display different colorsfrom each other. In one example, the main pixel MP comprises a red pixelthat displays red, a green pixel that displays green, and a blue pixelthat displays blue as sub-pixels PX. The main pixel MP may also comprisea white pixel that displays white color.

In one example, 60 to 70 main pixels MP are disposed along the firstdirection X and 60 to 70 main pixels MP are disposed along the seconddirection Y on one sensor electrode Rx.

FIG. 4 shows a basic configuration and equivalent circuit of the pixelPX.

A plurality of scanning lines G are connected to a scanning line drivecircuit GD. A plurality of signal lines S are connected to a signal linedrive circuit SD. Note that the scanning lines G and the signal lines Sdo not necessarily have to extend in a straight line, and some of themmay be bent. For example, the signal line S is assumed to extend in thesecond direction Y even if a part of it is bent.

A common electrode CE is provided for each sensor block B. The commonelectrodes CE are connected to a voltage supply unit CD of the commonvoltage (Vcom) and are arranged over a plurality of pixels PX. Each ofthe common electrodes CE is also connected to the touch controller TC asdescribed above, and form the sensor electrode Rx to which the touchdrive voltage is applied in the touch sensing mode.

Each pixel PX comprises a switching element SW, a pixel electrode PE, acommon electrode CE, and a liquid crystal layer LC, etc. The switchingelement SW is configured by a thin-film transistor (TFT), for example,and is electrically connected to the scanning line G and the signal lineS. The scanning line G is connected to the switching element SW in eachof the pixels PX lined up in the first direction X. The signal line S isconnected to the switching element SW in each of the pixels PX lined upin the second direction Y. The pixel electrode PE is electricallyconnected to the switching element SW. Each of the pixel electrodes PEfaces the common electrode CE, and drives the liquid crystal layer LC byan electric field generated between the pixel electrode PE and thecommon electrode CE. A holding capacitor CS is formed, for example,between an electrode of the same potential as the common electrode CEand an electrode of the same potential as the pixel electrode PE.

FIG. 5 is a plan view showing an example of a pixel layout.

The scanning lines G1 and G2 each extend linearly along the firstdirection X, and are lined up at intervals in the second direction Y.The signal lines S1 to S3 each extend generally along the seconddirection Y, and are lined up at intervals in the first direction X. Thedisplay panel PNL comprises metal lines ML1 to ML3 extending generallyalong the second direction Y and lined up at intervals in the firstdirection X. The metal lines ML1 to ML3 extend in a manner overlappingthe signal lines S1 to S3, respectively. Each of the metal lines ML1 toML3 has a first portion PT1 extending generally in the second directionY and a second portion PT2 having a width W12 larger than a width W11 ofthe first portion PT1 in the first direction X. The second portion PT2corresponds to an extended portion that is extended to connect with thecommon electrode CE.

Pixel electrodes PE1 and PE2 are disposed between the scanning lines G1and G2. The pixel electrodes PE1 and PE2 are lined up along the firstdirection X. The pixel electrode PE1 is disposed between the signallines S1 and S2, and the pixel electrode PE2 is disposed between thesignal lines S2 and S3.

The pixel electrodes PE1 and PE2 include strip electrodes Pa1 and Pa2,respectively. Each of the strip electrodes Pa1 and Pa2 has a portionextending along the direction D1 and a portion extending along thedirection D2. In the example shown in the drawing, there are four stripelectrodes Pa1 and Pa2 respectively. However, the strip electrodes Pa1and Pa2 may each be three or less, or five or more.

The common electrode CE is disposed over the pixels PX1 and PX2. Thecommon electrode CE is included in one sensor electrode Rx shown in FIG.2. The common electrode CE is superposed on the signal lines S1 to S3.In the example shown in the drawing, the common electrode CE is notsuperposed on the scanning lines G1 and G2. The pixel electrodes PE1 andPE2 are superposed on the common electrode CE.

FIG. 6 is a plan view showing the periphery of a subspacer SSP. In theexample shown in the drawing, the display panel PNL comprises theabove-mentioned metal lines ML1 to ML3 and scanning line G2, metalelectrodes ME1 and ME2, an insulating film 15, the light-shielding layerBM, and the subspacer SSP.

The metal electrode ME1 is located between the metal line ML1 and themetal line ML2 and is formed in an island shape. The metal electrode ME2is located between the metal line ML2 and the metal line ML3 and isformed in an island shape.

The insulating film 15 is disposed on almost the entire surface of thedisplay panel PNL. The insulating film 15 comprises a band-shaped firstthick film portion 61 extending in the first direction X, and aplurality of island-shaped second thick film portions 62. In FIG. 6, thearea where the first thick film portion 61 and the second thick filmportion 62 are located is indicated by diagonal lines. The first thickfilm portion 61 overlaps the scanning line G2 and the metal electrodesME1 and ME2. The plurality of second thick film portions 62 overlap withthe second portion PT2 of the metal lines ML1 to ML3, respectively.

The insulating film 15 has a contact hole (a first contact hole) CH11overlapping the metal electrode ME1, a contact hole CH12 overlapping themetal electrode ME2, and a contact hole (a second contact hole) CH13overlapping the second portion PT2. The contact holes CH11 and CH12 areformed in the first thick film portion 61. The contact hole CH13 isformed in the second thick film portion 62.

The first thick film portion 61 includes end portions 61A and 61Bextending in the first direction X. The end portion 61A is located onthe scanning line G2 side of the contact hole CH11, and the end portion61B is located on the opposite side of the end portion 61A. A width W1between the contact hole CH11 and the end portion 61A is 2 μm or more.Similarly, a width W2 between the contact hole CH11 and the end portion61B is 2 μm or more. In addition, a width W3 between the contact holeCH13 and the outer edge of the second thick film portion 62 is 1 to 3μm.

The light-shielding layer BM includes a first light-shielding portionBM1 overlapping the first thick film portion 61 and extending in thefirst direction X, a second light-shielding portion BM2 overlapping themetal lines ML1 to ML3 and extending in the second direction Y, and alight-shielding extended portion BM3 located at an intersection of thefirst light-shielding portion BM1 and the second light-shielding portionBM2 which overlaps with the metal line ML2. The first light-shieldingportion BM1 also overlaps with the scanning line G2 and the metalelectrodes ME1 and ME2. The second light-shielding portion BM2 alsooverlaps with the signal lines S1 to S3 shown in FIG. 5. In addition,the second portion PT2 of each of the metal lines ML1 to ML3 overlapswith the second light-shielding portion BM2. A width W13 of the firstlight-shielding portion BM1 along the second direction Y is larger thana width W14 of the second light-shielding portion BM2 along the firstdirection X. The light-shielding extended portion BM3 is extended in thesecond direction Y more than the first light-shielding portion BM1 andis extended in the first direction X more than the secondlight-shielding portion BM2 in planar view. The area that does notoverlap with the first light-shielding portion BM1, the secondlight-shielding portion BM2, and the light-shielding extended portionBM3 corresponds to a transmissive area of the pixel.

The width W13 of the first light-shielding portion BM1 along the seconddirection Y is larger than a width W15 of the first thick film portion61 along the second direction Y. In addition, the end portion 61A andthe end portion 61B of the first thick film portion 61 overlap with thefirst light-shielding portion BM1. That is, the first thick film portion61 is not exposed from the first light-shielding portion BM1. The firstlight-shielding portion BM1 includes end portions BMA and BMB extendingin the first direction X. The end portion BMA is located on the scanningline G2 side of the contact hole CH11, and the end portion BMB islocated on the opposite side of the end portion BMA. A width W21 betweenthe end portion 61A and the end portion BMA is 1 to 3 μm. Similarly, awidth W22 between the end portion 61B and the end portion BMB is 1 to 3μm. The second thick film portion 62 overlaps with the secondlight-shielding portion BM2. A part of the second thick film portion 62may be exposed from the second light-shielding portion BM2.

The subspacer SSP overlaps with the first thick film portion 61. Thesubspacer SSP overlaps with the light-shielding extended portion BM3 andthe metal line ML2.

FIG. 7 is a cross-sectional view of the display panel PNL taken alongline A-B shown in FIG. 6.

The first substrate SUB1 comprises an insulating substrate 10,insulating films 11 to 16, a semiconductor layer SC, the scanning lineG2, the signal line S2, the metal line ML2, the common electrode CE, thepixel electrode PE, and an alignment film AL1.

The insulating substrate 10 is a light transmissive substrate such as aglass substrate or a flexible resin substrate. The insulating film 11 islocated on the insulating substrate 10. The semiconductor layer SC islocated on the insulating film 11. The semiconductor layer SC is formed,for example, by polycrystalline silicon, but may also be formed byamorphous silicon or an oxide semiconductor. The insulating film 12covers the semiconductor layer SC and is located on the insulating film11.

The scanning line G2 is located on the insulating film 12. The scanningline G2 is formed by metal materials such as aluminum (Al), titanium(Ti), silver (Ag), molybdenum (Mo), tungsten (W), copper (Cu), chromium(Cr), etc., or an alloy combining these metal materials. It may be asingle-layer structure or a multi-layer structure. In one example, thescanning line G2 is formed of a molybdenum-tungsten alloy. Theinsulating film 13 covers the scanning line G2 and is located on theinsulating film 12.

The signal line (first signal line) S2 is located on the insulating film13. The signal line S2 is formed by metal materials such as aluminum(Al), titanium (Ti), silver (Ag), molybdenum (Mo), tungsten (W), copper(Cu), chromium (Cr), etc., or an alloy combining these metal materials.It may be a single-layer structure or a multi-layer structure. In oneexample, the signal line S2 is a stacked layer body in which a firstlayer containing titanium (Ti), a second layer containing aluminum (Al),and a third layer containing titanium (Ti) are stacked in this order.The insulating film (first insulating film) 14 covers the signal line S2and is located on the insulating film 13.

The metal line (first metal line) ML2 is located on the insulating film14. The metal line ML2 is formed by the above metal materials or analloy combining the above metal materials, and may be a single-layerstructure or a multi-layer structure. In one example, the metal line ML2is a stacked layer body in which a first layer containing titanium (Ti),a second layer containing aluminum (Al), and a third layer containingtitanium (Ti) are stacked in this order, or a stacked layer body inwhich a first layer containing molybdenum (Mo), a second layercontaining aluminum (Al), and a third layer containing molybdenum (Mo)are stacked in this order. The insulating film (second insulating film)15 covers the metal line ML2 and is located on the insulating film 14.The insulating film 15 protrudes toward the second substrate SUB2 at thefirst thick film portion 61.

The common electrode CE is located on the insulating film 15. The commonelectrode CE is a transparent electrode formed by a transparentconductive material such as indium tin oxide (ITO) or indium zinc oxide(IZO). The insulating film (third insulating film) 16 covers the commonelectrode CE and is located on the insulating film 15. The insulatingfilm 16 covers the first thick film portion 61.

The pixel electrode PE is located on the insulating film 16. The pixelelectrode PE is a transparent electrode formed by a transparentconductive material such as ITO or IZO. The alignment film AL1 coversthe pixel electrode PE and is located on the insulating film 16. Thealignment film AL1 covers the first thick film portion 61 via theinsulating film 16.

The insulating films 11 to 13 and the insulating film 16 are inorganicinsulating films formed by inorganic insulating materials such assilicon oxide, silicon nitride, silicon oxynitride, etc., and may be asingle-layer structure or a multi-layer structure. The insulating films14 and 15 are organic insulating films formed by, for example, organicinsulating materials such as acrylic resin.

The second substrate SUB2 comprises an insulating substrate 20, thelight-shielding layer BM, the color filter layer CF, an overcoat layerOC, the subspacer SSP, and an alignment film AL2.

Similar to the insulating substrate 10, the insulating substrate 20 is alight transmissive substrate such as a glass substrate or a resinsubstrate. The light-shielding layer BM and the color filter layer CFare located on a side of the insulating substrate 20 facing the firstsubstrate SUB1. The color filter layer CF includes a color filter CF1 ofa first color and a color filter CF2 of a second color. The color filterlayer CF further includes a color filter of a third color, which is notshown in the drawing. The first color, the second color, and the thirdcolor are different from each other. In one example, the first, thesecond, and the third colors are one of red, green, and blue.

The overcoat layer OC covers the color filter layer CF. The overcoatlayer OC is formed by a transparent resin. The subspacer SSP is providedunder the overcoat layer OC and protrudes toward the first substrateSUB1. The subspacer SSP is separated from the first substrate SUB1. Thealignment film AL2 covers the overcoat layer OC. The alignment films AL1and AL2 are formed, for example, by a material that exhibits horizontalalignment property.

The above-described first substrate SUB1 and second substrate SUB2 aredisposed so that the alignment films AL1 and AL2 face each other. Thefirst substrate SUB1 and the second substrate SUB2 are bonded by sealingin a state where a predetermined cell gap is formed. The liquid crystallayer LC is located between the first substrate SUB1 and the secondsubstrate SUB2. The liquid crystal layer LC comprises liquid crystalmolecules LM. The liquid crystal layer LC is configured by a positivetype (positive dielectric constant anisotropy) liquid crystal materialor a negative type (negative dielectric constant anisotropy) liquidcrystal material.

An optical element OD1 including a polarizing plate PL1 is bonded to theinsulating substrate 10. An optical element OD2 including a polarizingplate PL2 is bonded to the insulating substrate 20. Note that theoptical elements OD1 and OD2 may also comprise retardation plates,scattering layers, anti-reflection layers, etc., as necessary.

In such a display panel PNL, in an off-state where no electric field isformed between the pixel electrode PE and the common electrode CE, theliquid crystal molecules LM are initially aligned in a predetermineddirection between the alignment films AL1 and AL2. In such an off-state,the light irradiated from an illumination device IL toward the displaypanel PNL is absorbed by the optical elements OD1 and OD2, resulting ina dark display. On the other hand, in an on-state where an electricfield is formed between the pixel electrode PE and the common electrodeCE, the liquid crystal molecules LM are aligned in a direction differentfrom the initially aligned direction by the electric field, and thealignment direction is controlled by the electric field. In such anon-state, a part of the light from the illumination device IL passesthrough the optical elements OD1 and OD2, resulting in a bright display.

A first effect of the present embodiment will now be explained.

FIG. 8 is a cross-sectional view showing a state in which an externalforce is applied to the display panel PNL shown in FIG. 7. In thedrawing, the external force is indicated by arrows.

In some cases, the display panel PNL may be bent by an external forceand cause the subspacer SSP to scratch and damage the alignment film AL1in the lateral direction. In the area where the alignment film AL1 isdamaged, alignment disorder occurs in which the alignment of the liquidcrystal molecules differs from the desired alignment. When the subspacerSSP is returned to its original position, in a case where the area inwhich the alignment disorder has occurred does not overlap with thelight-shielding layer BM, light leakage of the display panel PNL occurs.In addition, if the light-shielding layer BM is extended to cover thedamaged portion of the alignment film AL1, the transmittance of thepixels will be reduced.

According to the present embodiment, the first substrate SUB1 comprisesthe first thick film portion 61 formed on the insulating film 15. Thesubspacer SSP faces the first thick film portion 61. Therefore, when anexternal force is applied to the display panel PNL, as is shown in FIG.8, the subspacer SSP abuts the first substrate SUB1 on the first thickfilm portion 61, but is separated from the first substrate SUB1 at aposition where it does not overlap with the first thick film portion 61.In other words, this allows the alignment film AL1 from being damaged bythe subspacer SSP outside the first thick film portion 61. Accordingly,the area in which the subspacer SSP may damage the alignment film AL1can be reduced. Therefore, the area of the light-shielding extendedportion BM3 for covering the damaged area of the alignment film AL1 canbe reduced, thereby improving the transmittance of the pixel.

In some cases, in the configuration of the present embodiment, thealignment film AL1 located on the first thick film portion 61 may bedamaged. Therefore, as shown in FIG. 6, the first light-shieldingportion BM1 covers the first thick film portion 61. Therefore, the lightleakage of the display panel PNL due to the alignment disorder on thefirst thick film portion 61 can be suppressed.

FIG. 9 is a cross-sectional view of the display panel PNL taken alongline C-D shown in FIG. 6. Note that, in FIG. 9, the layer between theinsulating substrate 10 and the insulating film 13 is collectivelyreferred to as a configuration layer 30. The configuration layer 30includes the above-mentioned insulating films 11 and 12, semiconductorlayer SC, and scanning line G2, etc.

In addition to the above-mentioned configuration, the first substrateSUB1 comprises the signal line S1, a drain electrode DE, the metal lineML1, the metal electrode ME1, and a transparent electrode TE, etc. Thedrain electrode DE and the signal lines S1 and S2 are located on theinsulating film 13 and covered by the insulating film 14. The drainelectrode DE is formed by the same material as the signal lines S1 andS2. The drain electrode DE is disposed between the signal lines S1 andS2.

The metal electrode ME1 and the metal lines ML1 and ML2 are located onthe insulating film 14 and covered by the insulating film 15. The metalelectrode ME1 is formed by the same material as the metal lines ML1 andML2. The metal electrode ME1 is in contact with the drain electrode DEat the contact hole CH1 formed in the insulating film 14. The contacthole CH1 penetrates the insulating film 14 to the drain electrode DE.

The transparent electrode TE and the common electrode CE are located onthe insulating film 15 and covered by the insulating film 16. Thetransparent electrode TE is formed by the same material as the commonelectrode CE. The transparent electrode TE is in contact with the metalelectrode ME1 at the contact hole CH11 formed in the insulating film 15.The common electrode CE is in contact with the metal line ML2 at thecontact hole CH13 formed in the insulating film 15. The contact holeCH11 penetrates the first thick film portion 61 to the metal electrodeME1. The contact hole CH13 penetrates the second thick film portion 62to the metal line ML2. The common electrode CE overlaps with the secondthick film portion 62.

The pixel electrode PE is located on the insulating film 16 and coveredby the alignment film AL1. The pixel electrode PE is in contact with thetransparent electrode TE at the contact hole (third contact hole) CH2formed in the insulating film 16. The contact hole CH2 penetrates theinsulating film 16 to the transparent electrode TE. The drain electrodeDE, the metal electrode ME1, the transparent electrode TE, and the pixelelectrode PE overlap in the third direction Z.

The first thick film portion 61 has a first thickness T1. The secondthick film portion 62 has a second thickness T2. The insulating film 15has a film thickness TH between the first thick film portion 61 and thesecond thick film portion 62. The first thickness T1 and the secondthickness T2 are each larger than the film thickness TH. The firstthickness T1 corresponds to a gap between the highest position of thefirst thick film portion 61 and the insulating film 14. The secondthickness T2 corresponds to a gap between the highest position of thesecond thick film portion 62 and the insulating film 14. The firstthickness T1 and the second thickness T2 are equal to each other.

A second effect of the present embodiment will now be explained.

The contact holes CH11 and CH13 are collectively formed by forming amask with holes on the insulating film 15 and then exposing it. However,for example, in a case where the thickness of the insulating film 15 isdifferent at positions where the respective contact holes CH11 and CH13are to be formed, the amount of exposure required to form the respectivecontact holes CH11 and CH13 will be different. Therefore, if theexposure is made in accordance with the film thickness of a positionwhere one of the contact holes is to be formed, problems such asdeformation, non-penetration, and dimensional deviation and variationmay occur for the other contact hole.

According to the present embodiment, the second thick film portion 62 isformed at a position where the contact hole CH13 is formed. In addition,the first thickness T1 of the first thick film portion 61 and the secondthickness T2 of the second thick film portion 62 are equal to eachother. Therefore, even if the contact holes CH11 and CH13 are formedwith the same amount of exposure, it is possible to suppress thedeformation, non-penetration, and dimensional deviation and variation,etc., of the contact hole.

Note that, in the present embodiment, the first thick film portion 61and the second thick film portion 62 are formed on an organic insulatingfilm; however, it is not limited to this example, and the first thickfilm portion 61 and the second thick film portion 62 can be formed onany inorganic insulating film having a certain film thickness or more.That is, the insulating film 15 may be an inorganic insulating film witha certain film thickness or more. In addition, the first thick filmportion 61 and the second thick film portion 62 are disposed in the samepattern as described above even in pixels where the subspace SSP is notdisposed.

FIG. 10 is a plan view showing the periphery of a main spacer MSP. Notethat, since the main spacer MSP is disposed at a position different fromthe subspacer SSP, symbols of members in the periphery of the mainspacer MSP are changed. However, the configurations other than the mainspacer MSP and the light-shielding extended portion BM3 are the same asthose shown in FIG. 6.

The main spacer MSP overlaps with the first thick film portion 61.Furthermore, the main spacer MSP overlaps with the light-shieldingextended portion BM3 and the metal line ML12. The area of thelight-shielding extended portion BM3 overlapping the main spacer MSP is,for example, formed larger than the area of the light-shielding extendedportion BM3 overlapping the subspacer SSP. Furthermore, the area of themain spacer MSP is formed smaller than the area of the subspacer SSP inplanar view.

The display panel PNL comprises a plurality of main spacers MSP and aplurality of subspacers SSP. The number of main spacers MSP is smallerthan the number of sub-spacers SSP. In a case where the display panelPNL is used in a personal computer, one main spacer MSP is disposed for,for example, four main pixels. On the other hand, the number ofsubspacers SSP as shown in FIG. 6 is, for example, disposed six to seventimes the number of main spacers MSP. Furthermore, in a case where thedisplay panel PNL is used in a mobile device, one main spacer MSP isdisposed for, for example, 16 main pixels. On the other hand, the numberof subspacers SSP as shown in FIG. 6 is, for example, disposed 14 to 15times the number of main spacers MSP. Note that the number of these mainspacers MSP and sub-spacers SSP is an example, and may be set in a ratioother than the above.

FIG. 11 is a cross-sectional view of the display panel PNL taken alongline E-F shown in FIG. 10.

The main spacer MSP is provided under the overcoat layer OC andprotrudes toward the first substrate SUB1. The main spacer MSP abuts thefirst substrate SUB1 in a state where no external force is applied tothe display panel PNL. That is, the main spacer MSP is in contact withthe alignment film AL1 at a position overlapping the first thick filmportion 61.

The same effect as the subspacer SSP described above can be obtained foralso the main spacer MSP.

Second Embodiment

FIG. 12 is a plan view of the periphery of a subspacer SSP. Theconfiguration shown in FIG. 12 is different from the configuration shownin FIG. 6 in that a first thick film portion 61 has a thick filmextended portion 612.

The first thick film portion 61 has a band-shaped portion 611 thatoverlaps with a first light-shielding portion BM1 and a thick filmextended portion 612 that overlaps with a light-shielding extendedportion BM3. The thick film extended portion 612 is extended in thesecond direction Y more than the band-shaped portion 611 in planar view.The thick film extended portion 612 has a first outer edge EG1 and asecond outer edge EG2 located on the opposite side of the first outeredge EG1. In the example shown in the drawing, the first outer edge EG1and the second outer edge EG2 are arc-shaped in planar view. The firstouter edge EG1 and the second outer edge EG2 overlap with thelight-shielding extended portion BM3. The subspacer SSP overlaps withthe thick film extended portion 612.

The light-shielding extended portion BM3 has an outer edge BMC. A widthW23 between the first outer edge EG1 and the outer edge BMC may be equalto or greater than the width W21 shown in FIG. 6. Furthermore, a widthW24 between the second outer edge EG2 and the outer edge BMC may beequal to or greater than the width W22 shown in FIG. 6.

FIG. 13 is a plan view of the periphery of the main spacer MSP. Theconfiguration shown in FIG. 13 is different from the configuration shownin FIG. 10 in that the first thick film portion 61 has the thick filmextended portion 612. In addition, the configuration shown in FIG. 13differs from the configuration shown in FIG. 12 mainly in that the areasof the light-shielding portion BM3 and the thick film extended portion612 are larger.

The main spacer MSP overlaps with the thick film extended portion 612.The thick film extended portion 612 overlaps with metal electrodes ME11and ME12, and contact holes CH21 and CH22 are formed in the thick filmextended portion 612.

The width W23 between the first outer edge EG1 and the outer edge BMCmay be equal to or greater than the width W21. Furthermore, the widthW24 between the second outer edge EG2 and the outer edge BMC may beequal to or greater than the width W22.

Third Embodiment

FIG. 14 shows dummy lines D41 and D42. FIG. 14(a) is a plan view of thedummy lines D41 and D42.

FIG. 14(b) is a cross-sectional view taken along the dummy lines D41 andD42.

As shown in FIG. 14(a), a signal line (second signal line) S4 extendsgenerally in the second direction Y. The dummy lines (first dummy lineand second dummy line) D41 and D42 extend in a manner overlapping thesignal line S4. An insulating film 15 comprises an island-shaped thirdthick film portion 63 located between the dummy lines D41 and D42, and adummy contact hole CH33 overlapping the third thick film portion 63.That is, the dummy contact hole CH33 is located between the dummy linesD41 and D42. A second light-shielding portion BM2 overlaps with thesignal line S4, the dummy lines D41 and D42, the third thick filmportion 63, and the dummy contact hole CH33.

As shown in FIG. 14(b), the signal line S4 is located on an insulatingfilm 13 and is covered by an insulating film 14. The dummy lines D41 andD42 are disposed between the insulating film 14 and an insulating film15. The dummy lines D41 and D42 are separated from each other atpositions overlapping a common electrode CE. The dummy contact hole CH33penetrates the third thick film portion 63 to the insulating film 14.The common electrode CE is in contact with the insulating film 14 in thedummy contact hole CH33. The third thick film portion 63 has a thirdthickness T3. The third thickness T3 is larger than the film thicknessTH of the insulating film 15 between the first thick film portion 61 andthe second thick film portion 62 shown in FIG. 9. The third thickness T3corresponds to a gap between the highest position of the third thickfilm portion 63 and the insulating film 14. The third thickness T3 isequal to the first thickness T1 and the second thickness T2 shown inFIG. 9.

As shown in FIG. 14, by forming the dummy contact hole CH33 even at apoint where the common electrode CE is not connected to the metal line,the film thickness can be made uniform when applying the alignment filmAL1.

Fourth Embodiment

FIG. 15 shows a metal line ML4. FIG. 15(a) is a plan view of the metalline ML4. FIG. 15(b) is a cross-sectional view taken along the metalline ML4.

As shown in FIG. 15(a), the metal line (second metal line) ML4 extendsgenerally in the second direction Y. An insulating film 15 comprises anisland-shaped fourth thick film portion 64 that overlaps with the metalline ML4. A second light-shielding portion BM2 overlaps with the metalline ML4 and the fourth thick film portion 64.

As shown in FIG. 15(b), a signal line S5 is located on an insulatingfilm 13 and is covered by an insulating film 14. The metal line ML4 isdisposed between the insulating film 14 and an insulating film 15. Acommon electrode CE overlaps with the fourth thick film portion 64. Thecommon electrode CE and the metal line ML4 are separated from each otherin the entire area of the fourth thick film portion 64. The fourth thickfilm portion 64 has a fourth thickness T4. The fourth thickness T4 islarger than the thickness TH of the insulating film 15 between the firstthick film portion 61 and the second thick film portion 62 shown in FIG.9. The fourth thickness T4 corresponds to a gap between the highestposition of the fourth thick film portion 64 and the insulating film 14.The fourth thickness T4 is equal to the first thickness T1 and thesecond thickness T2 shown in FIG. 9.

As shown in FIG. 15, the fourth thick film portion 64 may be formed evenat a point where the common electrode CE is not connected to the metalline ML4.

As explained above, according to the present embodiment, it is possibleto obtain a display device capable of improving the transmittance ofpixels.

The term “equal thickness” described herein means that the thickness isdesigned to be equal, and allows for slight differences in thicknessthat occur in the manufacturing process.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A display device comprising a first substrate, asecond substrate facing the first substrate, and a liquid crystal layerlocated between the first substrate and the second substrate, whereinthe first substrate comprises: a scanning line extending in a firstdirection; a first signal line extending in a second directionintersecting the first direction; a first insulating film covering thefirst signal line; a first metal line disposed on the first insulatingfilm and extending in a manner overlapping the first signal line; anisland-shaped metal electrode disposed on the first insulating film andformed by the same material as the first metal line; a second insulatingfilm covering the first metal line and the metal electrode; and a commonelectrode disposed on the second insulating film, the second insulatingfilm comprises: a band-shaped first thick film portion extending in thefirst direction and overlapping the scanning line and the metalelectrode; an island-shaped second thick film portion overlapping thefirst metal line and the common electrode; a first contact holepenetrating the first thick film portion to the metal electrode; and asecond contact hole penetrating the second thick film portion to thefirst metal line, a first thickness of the first thick film portion anda second thickness of the second thick film portion are larger than afilm thickness of the second insulating film between the first thickfilm portion and the second thick film portion, and the second substratecomprises a spacer that protrudes toward the first substrate andoverlaps the first thick film portion.
 2. The display device of claim 1comprising: a transparent electrode disposed on the second insulatingfilm and formed by the same material as the common electrode; a thirdinsulating film covering the common electrode and the transparentelectrode; and a pixel electrode disposed on the third insulating film,wherein the transparent electrode is in contact with the metal electrodevia the first contact hole, the common electrode is in contact with thefirst metal line via the second contact hole, and the pixel electrode isin contact with the transparent electrode via a third contact holeformed in the third insulating film.
 3. The display device of claim 1,wherein the first thickness and the second thickness are equal to eachother.
 4. The display device of claim 1 further comprising: alight-shielding layer including a first light-shielding portionoverlapping the first thick film portion and extending in the firstdirection, and a second light-shielding portion overlapping the firstmetal line and extending in the second direction, wherein the secondthick film portion overlaps with the second light-shielding portion, anda width along the second direction of the first light-shielding portionis larger than a width along the second direction of the first thickfilm portion.
 5. The display device of claim 4, wherein thelight-shielding layer comprises a light-shielding extended portionlocated at an intersection of the first light-shielding portion and thesecond light-shielding portion, the light-shielding extended portion, inplanar view, is extended in the second direction more than the firstlight-shielding portion and extended in the first direction more thanthe second light-shielding portion, and the spacer overlaps with thelight-shielding extended portion.
 6. The display device of claim 5,wherein the first thick film portion includes a band-shaped portionoverlapping the first light-shielding portion and a thick film extendedportion overlapping the light-shielding extended portion, the thick filmextended portion, in planar view, is extended more in the seconddirection than the band-shaped portion, and includes a first outer edgeand a second outer edge located on an opposite side of the first outeredge, the first outer edge and the second outer edge overlap with thelight-shielding extended portion, and the spacer overlaps with the thickfilm extended portion.
 7. The display device of claim 1, wherein thespacer is separated from the first substrate.
 8. The display device ofclaim 1, wherein the spacer abuts the first substrate.
 9. The displaydevice of claim 1 further comprising: a second signal line extending inthe second direction and covered by the first insulating film; and afirst dummy line and a second dummy line disposed between the firstinsulating film and the second insulating film and extending in a manneroverlapping the second signal line, wherein the second insulating filmcomprises an island-shaped third thick film portion located between thefirst dummy line and the second dummy line, and a dummy contact holepenetrating the third thick film portion to the first insulating film, athird thickness of the third thick film portion is larger than a filmthickness of the second insulating film between the first thick filmportion and the second thick film portion, and the common electrode isin contact with the first insulating film in the dummy contact hole. 10.The display device of claim 1 further comprising: a second metal linedisposed between the first insulating film and the second insulatingfilm and extending in the second direction, wherein the secondinsulating film comprises an island-shaped fourth thick film portionoverlapping the second metal line and the common electrode, a fourththickness of the fourth thick film portion is larger than a filmthickness of the second insulating film between the first thick filmportion and the second thick film portion, and the common electrode andthe second metal line are separated from each other in an entire area ofthe fourth thick film portion.
 11. The display device of claim 1,wherein the first metal line includes a first portion extending in thesecond direction and a second portion having a width larger than a widthof the first portion in the first direction, and the second thick filmportion overlaps with the second portion.
 12. The display device ofclaim 1, wherein the first insulating film and the second insulatingfilm are formed by an organic insulating material.